Oral insulin improves metabolic parameters in high fat diet fed rats

Abstract

Introduction/Aim: The gut has shown to have a pivotal role on the pathophysiology of metabolic disease. Food stimulation of distal intestinal segments promotes enterohormones secretion influencing insulin metabolism. In diabetic rats, oral insulin has potential to change intestinal epithelium behavior. This macromolecule promotes positive effects on laboratorial metabolic parameters and decreases diabetic intestinal hypertrophy. This study aims to test if oral insulin can influence metabolic parameters and intestinal weight in obese non-diabetic rats. Methods: Twelve weeks old Wistar rats were divided in 3 groups: control (CTRL) standard chow group; high fat diet low carbohydrates group (HFD) and HFD plus daily oral 20U insulin gavage (HFD+INS). Weight and food consumption were weekly obtained. After eight weeks, fasting blood samples were collected for laboratorial analysis. After euthanasia gut samples were isolated. Results: Rat oral insulin treatment decreased body weight gain (p<0,001), fasting glucose and triglycerides serum levels (p<0,05) an increased intestinal weight of distal ileum (P<0,05). Animal submitted to high fat diet presented higher levels of HOMA-IR although significant difference to CT was not achieved. HOMA-beta were significantly higher (p<0.05) in HFD+INS. Visceral fat was 10% lower in HFD+INS but the difference was not significant. Conclusions: In non-diabetic obese rats, oral insulin improves metabolic malfunction associated to rescue of beta-cell activity.

Insulin Nanocapsules Orally Administered in Hyperglycemia Rats Alter the Metabolic Profile and Intestinal Histomorphology / Alteração Do Perfil Metabólico E Histomorfometria Intestinal Em Ratos Hiperglicêmicos Tratados Com Nanocápsulas De Insulina via Oral

“…Conversely, HG-NPI showed significant reduction of retroperitoneal fat pads compared to HG-NP. A similar trend of reduction was observed by Lipinski [15] in nondiabetic rats receiving oral insulin treatment, and the authors argued whether topical insulin can directly impact gut epithelial lipid metabolism. Figure 5 shows the baseline blood glucose data of the animals.…”

“…The research showed a decrease in triglycerides in animals treated with gold nanoparticles coated with polysaccharide extracted from an apple. In a previous study, Lipinski [15] also observed a reduction in triglyceride levels with the use of oral regular insulin.…”

Association Between Exercise and Treatment with Liraglutide in Obese Rats by Cafeteria Diet

“…Blood was collected from animals and centrifuged at 3,000 rpm for 10 minutes, before measuring the following: a) glucose, b) triglycerides, c) total cholesterol, d) total proteins (all by enzymatic colorimetric methods) [25], and e) Plasma insulin, determined by radioimmunoassay [26].…”

Effect of Oral Insulin and Hyperlipidic Diet on Intestinal Epithelium and Adipose Tissue / Efeito Da Insulina Oral E Da Dieta Hiperlipídica No Epitélio Intestinal E Tecido Adiposo

“…Insulin is a peptide that has low bioavailability when administered orally due to its degradation in stomach pH. However, studies show that this hormone improves serum parameters and promotes morphologically changes in the intestinal epithelium [1,2].…”

“…In addition, insulin is able to act by reducing the weight of adipose tissue [2]. The cause of the inflammation in adipocytes caused by diabetes is not yet fully defined.…”